Cell death-inducing DFFA-like effector c (CIDEC, also known as Fsp27) has emerged as an important regulator of metabolism associated with lipodystrophy, diabetes, and hepatic steatosis. It is required for unilocular lipid droplet formation and optimal energy storage. The mechanism between this gene and livestock growth traits, however, has yet to be reported. In this study, we found ten novel single nucleotide polymorphisms (SNPs) in the 5' transcriptional region of CIDEC in Nanyang (NY) cattle, which are located in the recognition sequences (potential cis-acting elements) of 22 transcription factors, and the nine haplotypes represent nine different combinations of polymorphic potential cis-acting elements. THE RESULTSindicated that individuals with the H8-H8 diplotype had heavier body weights and faster growth rates (P?0.01) at 18th months than those with H1-H8. We evaluated the transcriptional activities of different haplotypes in vitro, the results were consistent with the association analysis. The H8 haplotype had 1. 88-fold (P?0. 001) higher transcriptional activity than the H1 haplotype. We speculate that the haplotypes of the potential cis-acting elements may affect the transcriptional activity of CIDEC, thus affecting the growth traits of cattle. This information may be used in molecular marker-assisted selection of cattle breeding in the future.